1. Test Inkscape (1.0, 1.1, 1.2) to see meaning of document properties metadata
2. Grep all Inkscape code, docs, manuals and etc. to find all elements ans attributes from sodipodi: and inkscape: namespaces
3. Test all Inkscape tools to find tool specific metadata
4. Search svg images created with old versions of Sodipodi and Inkscape to find old and obsolescent attributes and elements
